Does lack of 80% mortar coverage mean that a tile installation will fail? – Tech Talk – February 2018

By Tom D. Lynch, CSI

Not on your life! But you’d never know it by the way most professionals view this issue. The TCNA Handbook and ANSI A108 strongly recommend that 80% coverage should be attained for most installation scenarios, and rightfully so (exterior projects and showers recommend a minimum 95% coverage). The Handbook even goes so far as to offer explicit instructions as to how this can be obtained (thanks to Joe Tarver’s research years ago at the NTCA).

I agree wholeheartedly that the 80% goal should be reached on every tile installation; but I disagree that if it is not attained it will doom an installation to failure. I have seen too many installations that have been in for two years, three years and more that have never had the slightest inkling of failure until dramatic structural movement triggered lateral stress – most times as a crack in the concrete slab – that caused tile to dis-bond and shear loose. Then, if the coverage was something less than 80%, the tile contractor got blamed for the entire failure, or at least the vast majority of it. Never mind that the floor never failed for several years. Never mind that it is obvious that a crack in the concrete triggered the stress put on the mortar. It becomes the fault of the tile contractor because of the less-than-80%-coverage issue.

I disagree! I’m 100% on the side of the tile contractor here! Let me shed some needed light on this topic.

Let’s go back to the 1950s and ’60s when thin-set mortars were first being introduced to the market. ANSI was tasked with evaluating these new mortars that were beginning to replace full-blown mud-bed installations. ANSI A118.1 was developed, which included a porcelain tile shear strength rating of 150 psi. ANSI A118.4 came in at a porcelain shear of 200 psi. It was determined (and still is) that A118.4 has the desired mortar strength for installing porcelain tile. You with me so far?

Realizing that human beings are incapable of 100% perfection at all times, the Tile Council of America (now TCNA) and ANSI deemed it permissible to allow only 80% coverage for most installations. This is cool, but the one factor missing is that the ANSI testing is performed with 100% coverage on the test samples.

Oops! Now what?

If 100% coverage yields 200 psi, then it might be safe to assume that 80% coverage would yield only 160 psi. Make sense? Okay, so now let’s improve our installation mortar upwards to the newer A 118.15 mortars that achieve 400 psi shears with porcelain. 80% coverage with this mortar would yield a 320 psi shear strength which is exactly twice as strong as what A118.4 mortar achieves. This could also mean that only a 40% coverage rate with an A118.15 mortar would equal the required A118.4 rate of 160 psi at 80%.

What?? Am I suggesting that the rate of coverage be dropped to 40% minimums? Absolutely not! But what I am advocating is that if an installation has the tile edges and corners adequately supported and yet the coverage rate is something less than 80% it is NOT necessarily a cause for failure, and the tile contractor should be given the benefit of the doubt until the actual cause of the failure is discovered.

Up until now this 80% minimum coverage rate has been the death knell for tile contractors. It is unfair and needs to be stopped.

Here’s another point to consider. If the coverage on a particular failure was 80%-95% and a crack appeared in the slab causing the tile to shear loose, whose fault would it be? Obviously the concrete guy’s, right? So who can determine how much lateral stress the cracking of the concrete caused? 100psi, 200psi, 500psi, 1,000psi? It’s humanly impossible to determine, so let’s give the benefit of doubt to the tile contractor. Remember, when concrete cracks it’s generally like a mini explosion taking place – sudden and violent. It is never a silent and gradual separation.

I would venture a guess that there are more un-failed and completely successful tile installations in this country with less than 80% mortar coverage than there are with it. As professionals, let’s concentrate on solving failures rather than copping out by simply calculating coverage issues that more times than not unfairly condemn the tile installers.

Tom Lynch is a 55-year veteran of the tile industry and one of the NTCA’s initial Recognized Industry Consultants inductees. He can be reached at (336) 877-6951, [email protected] or at 

Tech Talk – January 2018

The TCNA Handbook for Ceramic, Glass and Stone Tile Installation

By The CTEF Blog

This article is the first of three articles that examine, explore and explain the documents and publications essential to the health of our industry: The TCNA Handbook, the ANSI Standards and the NTCA Reference Manual.

If you spend time with anyone involved in the proper installation of ceramic tile, the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation will be the focal point of the conversation. Why? Because this useful guide assists in clarifying and standardizing installation specifications for tile.

In addition to providing a selection of numbered installation “methods” for differentiating and easy reference, the Handbook includes various product selection guides for ceramic, glass, and stone tiles; guidelines for wet areas; field and installation requirements, and more.

Produced by the Tile Council of North America (TCNA), the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation has been published on a continuous basis since 1963.

Here’s an overview:

First, what is the TCNA?

Tile Council of North America is a trade association representing manufacturers of ceramic tile, tile installation materials, tile equipment, raw materials, and other tile-related products. It was established in 1945 as the Tile Council of America (TCA). In 2003, it became TCNA reflecting how its membership has expanded to include all of North America.

Tile Council is recognized for its leadership role in facilitating the development of North American and international industry quality standards to benefit tile consumers.

Additionally, TCNA regularly conducts independent research and product testing, works with regulatory, trade, and other government agencies, offers professional training, and publishes industry-consensus guidelines and standards, economic reports, and promotional literature.

One of the highlights of the yearly Coverings show is hearing TCNA Executive Director Eric Astrachan review the state of the ceramic tile industry – from an economic perspective as well as from a creative and trend perspective in North America.

TCNA also strongly supports the mission of the Ceramic Tile Education Foundation.

What is the TCNA Handbook for Ceramic, Glass, and Stone Tile Installation?

The TCNA website describes the Handbook as follows:

“A guide to assist in clarifying and standardizing installation specifications for tile. Each installation recommendation, or method, requires a properly designed, constructed, and prepared substructure using materials and construction techniques that meet nationally recognized material and construction standards. Included are: product selection guides for ceramic, glass, and stone tiles; guidelines for wet areas; ISO mortar and grout specifications; information on substrate flatness requirements; information on grout joint sizes and patterns, and workmanship standards excerpted from ANSI installation standards.”

The TCNA Handbook provides installation methods from which to choose, based on the requirements of the installation or the types of applications in which they may be used.

For example, will the tile be installed inside or outside? In a wet area such as a shower or steam room? Or in a dry area such as an entry foyer? Each method includes a generic drawing that shows each component or material required as you can see in the image below, which addresses installing stone floor tile.

How is the Handbook organized?

The TCNA Handbook works hand-in-hand with the ANSI Specifications to provide tile installations that are proven to stand the test of time.

In addition to detailing tile installation methods for ceramic and glass tile and natural stone tile, the Handbook includes:

  • Product selection guides for ceramic tile, glass tile, natural stone tile, setting materials, grout, backer board, membrane, additional products and Green Building
  • Field and installation requirements (i.e., substrate requirements, lighting, mortar and mortar coverage, flatness and lippage, grout joint size and pattern considerations, finished tilework, accessibility and wet areas guidelines)
  • Floor tiling installation guide
  • Environmental exposure classifications
  • Using the TCNA Handbook for specification writing
  • Installer and contractor qualifications guide
  • EJ171 Movement Joint Guidelines for Ceramic, Glass and Stone
  • Appendices and method locators

Each tile installation method details:

  • Recommended uses
  • Service rating
  • Environmental exposure classifications
  • Typical weight of tile installation
  • Limitations
  • Membrane options
  • Requirements
  • Materials (including for Green/Sustainable design)
  • Preparation by other trades
  • Movement joint requirements
  • Installation specifications
  • Notes
The evolution of the TCNA Handbook

The Handbook is truly a living, breathing entity that evolves in lock-step with the tile industry. As new products get introduced – for example, new tile formats and new mortars and tools to support those formats – new installations methods quickly follow to ensure best practices.

As a result, the Handbook has increased in size. A press release detailing changes in the 2017 issue includes the following:

  • The new sections “Tile Layout Considerations” and “System Modularity” are geared more toward those involved in tile selection and design. As an example of the various revisions to Handbook existing language, (Astrachan) noted the further explanation this year of substrate flatness requirements, which (he) calls “essential but too-often ignored.”
  • A prime example is the new Handbook section to address the newer type of steel studs commonly referred to as “equivalent gauge” or “EQ” studs. The new Handbook language helps people understand the most important considerations for avoiding tile problems when these thinner studs are used. Stephanie Samulski, Handbook Committee Secretary and Technical Content Manager, noted that “the specific design criteria that are ultimately needed will likely get hashed out in ANS.”
  • Other noteworthy changes that 2017 Handbook users will see include significantly more information on how to avoid the undesirable effects of wall-wash lighting on tile installations, new “Visual Inspection of Tilework” and “Design Considerations When Specifying Tile” sections, significant changes to the EJ171 movement joint guidelines, and a new method for tiling an exterior deck or balcony over unoccupied space (tile and stone versions).
What makes the Handbook unique?

The Handbook comes to life each year thanks to the Handbook Committee that includes representatives from the entire tile industry and all those touched by the tile industry – backer board, mortar, grout, membrane, tile and more manufacturers, industry associations, standards groups, construction specification groups and regional groups. It’s a balanced assembly of stakeholder voters that comes together to prioritize and address topics of concern.

The TCNA Handbook Committee determines Handbook content through significant group discussion and consensus efforts, and through meetings in person biennially and more frequently in workgroups.

As Astrachan explained, “The Handbook is a vehicle for providing industry consensus, but it’s not a standard and therefore not set up like one, enabling the committee to provide information in non-mandatory language when needed. It’s a particularly useful means of addressing conflicting recommendations or specifications, as can easily occur when a producer or another trade makes a major shift in product or practice in a way that impacts tile installations.”

Proposals for changes, often referred to as “submissions,” are welcome from any individual or organization.

Would you like to become involved in the TCNA Handbook?

All Handbook meetings are open to non-members, who are encouraged to participate in the discussions. If you would like to become involved, you can find meeting dates and locations posted on

Tech Talk – December 2017

Have you added tile edge protection to your installation project?

How often are you including tile edge protection in your tile assembly specifications? Although not required for all installations, edge protection absolutely provides better results.

By Scott Carothers,
CTEF Director of Certification
and Training

Ultimately, if you’re serious about delivering only high-quality installations of ceramic, porcelain and stone tile, you must have the hand-skills to put the entire tile assembly into place along with the knowledge of what products are available to finish the project successfully.

Thinking about protecting tile edges is a perfect example.

What is tile edge protection?

You wouldn’t be in this business if you didn’t have an appreciation for how perfectly ceramic and porcelain tile function as floor and wall finishes. Tile is beautiful, durable, and easily maintained.

It has an amazing performance record and inspires intense product innovation.

Critical to your well-earned reputation is ensuring that your tile installation will perform despite heavy traffic. Edge profiles do the following:

  • Protect tile edges from chipping,
  • Provide easy transitions between adjacent floor and wall surfaces.
  • Deliver a design element that is often ignored.
Specify each component of the tile assembly

On most commercial tile jobs, the specifications clearly call out each component of the tile assembly, but not always.

However, on many residential jobs, the various items necessary for a good job may be overlooked.

Whether the project is commercial or residential, the tile installer is the last person on the job who should provide his or her input and expertise so that the ceramic tile installation is pleasing to the eye and will stand the test of time.

Don’t skip the little details!

Unfortunately the ultimate success of the completed project sometimes gets lost in the rush to get it done yesterday or in the little details that sometimes fall through the cracks.

Whatever the reason, the edge profile moldings are sometimes not included in the job. And yet, as mentioned above, these profiles play two key roles:

To provide a pleasing transition to the adjacent floor finish

To protect the edge of the tile, which may be a factory edge or a cut

Lack of edge protection means chipped tile

As seen in the photo below, which was taken from a hotel breakfast area, the edge of the wood-look ceramic tile is significantly chipped after only a few years of service.

Without the metal profile to protect the edge of the tile, unsightly chipping can (and does) occur.

In this case, the combination of the housekeeper’s sweeper and the metal legged chairs has taken its toll on the tile.

Consider exacerbating conditions

As you may have noticed in the photo above, the low-pile commercial carpet is 1/8” of an inch below the edge of the tile. This factor would definitely exacerbate the problem.

This may be particularly challenging, because you may not know the carpet pile height when discussing and developing a mockup for the project. Unless you consider the various possibilities, you may overlook the right product needed to finish the project successfully.

The tile otherwise has served the area well and looks great, but the chipped tile along the edge makes the entire job look unsatisfactory and unacceptable.

The real problem here is that when consumers see problems of this type, they often decide not to use tile in their next project. Their rationale is simple. If tile looks and performs like this (as seen in the photo), they don’t want it and will pick something else, which means everyone in the tile industry loses the job.

Proactive input eliminates problems

A small amount of proactive input prior to the job beginning would have eliminated this problem.

Many times the installer is not consulted on the design end of the project. But in this case, the installer gets blamed for the ugly result when in reality, he or she had no part in the process. The really odd thing about this hotel upgrade project is that all of the other installed tile surfaces included edge profiles.

The point here is that, as an installer, you should speak up and make recommendations that will enhance the project outcome and be a long-lasting testimonial to the durability and beauty of properly installed ceramic tile.

Certification signals your commitment to details like tile edge protection

If you haven’t already, consider becoming a Certified Tile Installer (CTI). As a CTI, you set yourself apart from the crowd and know how to anticipate tile installation problems before they occur.

Do it right the first time and get paid accordingly. Visit for details.


Contractor Member Question


Is there a way to determine what a stain on the surface of a tile is? We run into this problem every once in awhile.  I currently have a job that has been complete for a few months and they have sent pictures claiming the spots are thinset, membrane or grout.  I do not believe they are any of those things. Is there a way to tell? Please advise.

Mark’s Response

A recognized tile consultant either owns, or has access to laboratory technology that can test deposits on the surface of tiles.
A list of NTCA’s recognized consultants can be found on the NTCA website at this link:
Any of the consultants listed on this page should be able to assist you.
I hope this helps.
Mark Heinlein
Technical Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein – 10/31/2017

Consumer Question:

Hello! I’m trying to find out if there is an industry standard for the conversion rate of m to kg for Porcelain tiles based on thickness and if so, where I would be able to find this information. Thank you in advance for your assistance.

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

The Tile Council of North America (TCNA) Handbook for Ceramic, Glass and Stone Tile Installation contains an Appendix (B) discussing “Estimated Weights for Floor Installations.”

This appendix provides a discussion of assumptions for dead load weights of ceramic and stone tile and related setting materials. The assumptions are given in terms of imperial / US Customary (pounds per square foot) measurement vice metric (kilograms per square meters).  Several tables giving the weight calculations for methods included in the handbook are provided in Appendix B.

If you do not own the TCNA Handbook, a copy can be purchased from the NTCA’s Online Store under the Industry Technical Manuals section at this link:

I hope this helps.


Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein – 10/24/2017

Member Question:

We are encountering issues with a wall tile installation. I am trying to find out what the wall assembly should consist of in regards to metal studs, horizontal reinforcement, etc.   Your response would be greatly appreciated.

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

Please refer to the Tile Council of North America (TCNA) Handbook Method W243-17 for the details and best practices for the wall installation you are dealing with.  This method requires metal studs to be well braced; 20 gauge (0.033”) or heavier; minimum depth 3-5/8” for commercial applications.  The gypsum board must meet ASTM C1396/C1396M with a minimum of 1/2” thickness for single layer applications and must be installed per GA-216.  Maximum allowable variation of the substrate (for the installation of 12”x12” tile) is to not exceed 1/4” in 10’ (feet) from the required plane with no more than 1/16” variation in 12” when measured from the high points in the surface.  Additionally, details for movement and expansion must be met as required by TCNA Handbook method EJ-171.

I have attached a photo of the section of the 2017 TCNA Handbook that discusses “Equivalent Gauge” Steel Framing in case that material has been used on this project.

In addition, the NTCA Reference Manual includes an excellent discussion of EQ Gauge steel framing.  It states, in part, that the wall framing should meet a deflection limit of L/360 for the rated load based on the properties of the stud alone.  It further states that it is the responsibility of the design professional and framing contractor to ensure that wall assemblies for tile and stone finishes are designed and assembled to meet performance requirements, and all manufacturers of EQ studs will have the technical data needed for design and confirmation of performance requirements.

I am glad to learn you will be joining the NTCA.  As a member, you will find many benefits including tremendous networking and educational opportunities with many likeminded tile industry professionals looking to improve their level of performance and education based on tile industry standards. Other benefits include receiving a copy of the TCNA Handbook and the NTCA Reference Manual each year with your membership renewal.  I look forward to discussing membership with you next week when you call back.  In the meantime, please visit for more information.  You can view additional member benefits at this link:  you can also join by clicking on the “Join Now” link found anywhere on our website.

I hope this helps!

Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Member Question:

I have a job where we installed a porcelain tile. It is 8” x 15” and the side walls are fine but the wet walls are not good.  The worst part is they have that system of lighting where it is shining down directly from above so it shows all discrepancies and shadows. Is there anything in the industry standards that allows for a tolerance for a little lippage?

Mark’s Response:

Thank you for contacting the National Tile Contractors Association.

The standard for lippage is found in ANSI A108.02 Section 4 (copy attached) and is echoed in the TCNA Handbook.  Generally speaking, 1/32” in addition to the allowable warpage of a tile manufactured in accordance with ANSI A137.1 is the allowable lippage for wall mount mosaics with a grout joint width of 1/16 – 1/8”.

I understand these strip mosaics can be difficult and time consuming to install.  You are correct that substrate flatness is the place to start to help ensure the installed lippage is within tolerance.

The NTCA Reference Manual has an excellent section describing Wash Wall Lighting and how to avoid problems that can be associated with it.  If you have your Reference Manual at hand, it will provide some good reading on this topic.

The 2017 TCNA Handbook contains a section on Visual Inspection of Finished Tilework.  I don’t have my book close at hand but it is in the first 30-40 pages.  It may help your situation that visual inspection of wall installations is performed at 36” from the tilework.  Please take a look at that section in the Handbook and see if it can work for you in this case.

Please let me know if I can help with any further questions you might have after you are able to review the documents I listed above.

I hope this helps!

Mark Heinlein

NTCA Training Director

Tech Tip Tuesday: Q & A With NTCA Training Director Mark Heinlein

Member Question:

I need installation guidance to install a ceramic or porcelain tile over a concrete slab/sidewalk. This will be outside of a church and it is currently a concrete floor and curb. What would you recommend we use at the edge and expansion joints?

Mark’s Response:

There is a lot to consider before tiling a project like this one.  Since you may not have yet received your 2017 TCNA Handbook, I have attached a couple of photos of two methods (F101 and F102) that may be most applicable to your installation.

F101 describes an on ground concrete substrate with proper drainage below the slab, bonded mortar bed, ceramic tile and optional waterproofing / crack isolation membrane.

F102 describes an on ground concrete substrate with proper drainage below the slab, cementitious bond coat and optional waterproofing / crack isolation membrane.

Both of these methods will require proper drainage beneath the slab and drainage for surface water runoff from the finished surface and further drainage into the landscaping.  If the slab abuts a permanent structure, you will want to be certain that the drainage is slope away from the structure – the general rule would be 1/4” vertical slope per 12” of horizontal run.  Besides methods F101 and F102, there may be other methods and materials that will help with system drainage if that is an issue.

Prior to proceeding you will need to determine if this is a well cured slab and whether it is dimensionally stable and free of cracks, films, curing compounds, sealers, etc. and whether it’s surface has been at least steel troweled with a fine broom finish suitable for mortar to bond to it.  The flatness requirements of 1/4” per 10’ must be met for application of an F101 Thick Mortar Bed or for F102 direct bonding of tiles less than 15” on one side.  For direct bonding of tiles with one side 15” or longer the slab must meet the 1/8” per 10’ flatness requirement before the tile (or membrane) is to be set.

You will see that both of these methods list a membrane as optional.  Inclusion of a membrane will help with waterproofing above the substrate and a degree of crack isolation from minor existing or future in-plane cracks.  If the slab is abutted to a structure, I suggest looking for a way to flash the membrane up the side of the structure, potentially beneath the siding (if any).  The “Membrane Options” section of the method lists the specific membrane requirements and also points to Handbook methods F125-Partial / F125 – Full for crack isolation.

Some membrane manufacturers state that their membranes will be able to span certain types of joints if installed per their instructions and as part of a full system warranty (use of one manufacturer’s mortar, grout, membrane, sealant, etc.).  Installation of a membrane will help with waterproofing, some system drainage, and to protect against efflorescence from the substrate.

The “Materials” section defines the specifications for the tile and setting materials to be used in this method.

You are correct that this installation will need Movement Accommodation Joints.  TCNA Handbook Method EJ-171 provides the details.  As a minimum, those joints should be placed around the perimeter and at every change in plane or where the tile meets a different material.  Expansion joints in the concrete slab must be honored upward through the finished surface of the tile.  Expansion, Isolation, Construction, Contraction and other joints must be addressed.  For an exterior installation, joints throughout the tile field are required every 8’ – 12’ depending on materials and environmental conditions.  Appropriate joint width must also be determined based on environmental conditions the installation is expected to be subject to.  Sealants complying with ASTM C920 with an appropriate designation for this type of installation will be required for the soft joints.  As this is a traffic area, a sealant with a shore A hardness rating of 25 or greater should be considered.  Conversely, a manufactured joint may be available to use.  As we discussed in our workshop, it is the responsibility of the design professional or engineer to determine the location / placement / width / construction of these joints.  Method EJ-171 provides details on constituting these joints – but is too much information for me to forward in this e-mail.

Since this is an exterior installation with some potential of freeze/thaw cycling, expect there to be some system / component degradation over time that may require routine maintenance.

You will want to finish and protect the exposed edges of the tile with a commercially rated, durable metal trim such as brass or stainless steel. Bullnose, or tiles that have been custom bullnosed for the project may also work well depending on the expected use and conditions.

I hope this helps point you in the right direction.  You should have your new 2017 TCNA Handbook soon so you can refer to these methods and all of the other great guidance it contains.

Mark Heinlein

NTCA Training Director


Contractor Question:

I am thinking about putting a heating TapeMat in the floor of my bathroom.  The manufacturer’s literature suggests a modified thin-set mortar.  I am using a large format tile (12” x 24”).  I am placing the tile on a 3/4 inch plywood subfloor with a 1/4 inch Hardy board backer.  The floor is supported by 2”x12” floor joists spaced at 16” on center.  The bathroom is L shaped and is  8’x4’ with a 3’ L.  The 8’ wall is an exterior wall. Would an unmodified mortar work as well? Is it even advisable to use a modified mortar with a large format tile?

Mark’s Reply:

Thanks for the info.

Assuming ceramic/porcelain tile is being installed, the industry recognized method found in TCNA Handbook is RH135-16.  The method describes the details for an electric radiant heat system encapsulated in mortar over backer board on a plywood subfloor with joists 16” on center, which is the installation you have described.

It sounds like you are not installing a waterproofing membrane in the system.  In that case, the required thinset mortar for the cementitious bond coat is an ANSI A118.15.  In other words, an Improved Modified Dry-Set Cement Mortar is required.

The mortar you select should have the words “Meets ANSI A118.15” stamped on the package.  Be certain to carefully follow the mortar manufacturer’s instructions for the proper amount of water, mixing instructions, slaking time, open time, etc.

You asked whether it is advisable to use a modified mortar with a large format tile.  It is.  In fact, many manufacturers are now producing highly modified mortars specifically designed for Large and Heavy Tile.  You may find mortars labeled as “LHT” for this reason.  These mortars have specific properties to support the installation of large and heavy tiles on floors and walls.  Some allow for a thicker bond coat.  This is the type of mortar I would look for when installing an electrical heating tape mat system in the bond coat layer.

If you are using a membrane in the system, it may be advisable to use a less highly modified mortar (such as an A118.4) or even an unmodified thinset mortar (A118.1).  Check with the manufacturer of the membrane for their specific mortar recommendation.

Please make certain the surface of your plywood subfloor is flat to meet the industry standard tolerance of 1/8” in 10’ as required by ANSI A108 before you install the backer board.  This will ensure you have a flat finished tile surface on your large format tile installation.  Use a rapid setting patch material to fill low spots and a belt sander on the high spots of the plywood.  Do not use more or less thinset to help you flatten your installation while you set tile.  Doing so will prove problematic for you and your installation.

Membership in the National Tile Contractors Association is a valuable resource for any professional tile contractor or any contractor who installs tile.  NTCA is committed to improving installations and performance of contractors throughout the tile industry.  Our primary mission is training based on the tile industry standards I have described above.  Every installer should own and be familiar with the standards, methods and details that guide the tile industry.  I would be happy to discuss with you and your tile installation contractors the many benefits of membership in NTCA.  Please feel free to contact me, or Jim Olson at [email protected] for more information.  Also please visit our website at

The Ceramic Tile Education Foundation (CTEF) supports education and training in the tile industry.  The Certified Tile Installer (CTI) program is a highly sought after certification for tile installers who wish to achieve a higher level of professionalism and recognition in the tile industry.  Please visit the CTEF website at to locate a Certified Tile Installer or contact Kevin Insalato at [email protected] for more information on how a contractor can become a CTI.

I hope this helps.

Mark Heinlein, NTCA Training Director


Tech Tip Tuesday: Q & A With NTCA Technical Trainer Robb Roderick


I have someone in Florida who is arguing that he has never heard of needing a crack suppression membrane for glass, particularly in pools. Can you suggest some verbiage here?


Thank you for contacting NTCA. On page 8 of the glass tile selection and installation guide in the TCNA handbook. It states, “glass tile is generally more vulnerable to crack propagation than ceramic tile. Where opacity allows, the glass tile manufacturer may recommend the use of a ANSI A118.12 crack isolation membrane for large format glass.

Also, on page 21 in the membrane selection guide, glass tile is listed as material in which  crack isolation membranes can eliminate cracks caused by in plane movement of the substrate.

On page 94 it shows method F125 for installation of crack isolation membranes. The handbook also shows Method P601 and P602 for pool and water features.


-Robb Roderick,

NTCA Technical Trainer

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